In prior turbine bodies, the internal high pressure (HP) and medium pressure (MP) stators are separated by a gap and each of them is provided with a separate sealing device, which devices are separate from each other and serve to reduce the natural leakage of steam from the HP stream to the MP stream. A portion of the leakage passes through the gap between the two sealing devices and is exhausted via the gap provided between the two internal stators in the inter-stator space. This space is thus swept with high temperature steam which is exhausted via thermal protection means.
This flow of steam serves to steam condition the internal and external stators, thereby making it possible to reduce the temperature of the external stator and thus making it possible to reduce its dimensions.
However, the steam conditioning performed in this way by steam sweeping is not perfect. The temperature of the steam injected into the inter-stator space is high, and as a result both the external stator and the fastenings of the HP and MP internal stators are at high temperature.